S --> wh C
S --> wh I
S --> NP I
S --> I2
S --> wh
S --> co
IP --> NP I2
C --> aux IP
C --> aux I2
I --> aux I2
I --> aux 
I2 --> NP
I2 --> VI
I2 --> AP
AP --> adj
NP --> det N
NP --> N
NP --> pro
NP --> prop
VI --> vi
N --> adj N
N --> n